Revelation 13:5

he was given a mouth speaking great things and blasphemies As we have seen throughout this book, the actions and duration of the agents of evil are subject to Gods sovereign permission (Rev. Rev. 13:7+, Rev. 13:14-15+ cf. Luke Luke 22:31). The great things which he speaks are the pompous words which Daniel saw the little horn speak (Dan. Dan. 7:8, Dan. 7:11, Dan. 7:20, Dan. 7:25). In his exaltation of himself, Daniel saw him speak blasphemies against the God of gods (Dan. Dan. 11:36). The great things and blasphemies likely speak of the same thing. The figure [of speech] is Hendiadys; for the great things are his blasphemies.1 See #25 - Little Horn.

forty-two months This period is equivalent to the time and times and half a time, a three and one-half year period during which Daniel saw that the saints would be given into the hand of the little horn (Dan. Dan. 7:25). 3 See Prophetic Year.

But when this Antichrist shall have devastated all things in this world, he will reign for three years and six months, and sit in the temple at Jerusalem; and then the Lord will come from heaven in the clouds, in the glory of the Father, sending this man and those who follow him into the lake of fire; but bringing in for the righteous the times of the kingdom, that is, the rest, the hallowed seventh day; and restoring to Abraham the promised inheritance, in which kingdom the Lord declared, that many coming from the east and from the west should sit down with Abraham, Isaac, and Jacob.Irenaeus, Against Heresies, v.xxx [emphasis added]4

3 Christs public ministry was limited to three years and a half; so also will the Antichrists final ministry be (Rev. Rev. 13:5+).Arthur Walkington Pink, The Antichrist (Oak Harbor, WA: Logos Research Systems, 1999, 1923), s.v. Comparisons between Christ and the Antichrist.